Centrifuges are customarily employed in the separation of cells and other solids from body fluids to permit subsequent diagnosis or analysis. Centrifuges presently in use are designed to accommodate a plurality of sample chambers and in such a way as to be capable of rapidly loading and unloading the chambers so as to facilitate more rapid and efficient sampling. One such centrifuge is the cytocentrifuge set forth and disclosed in U.S. Pat. No. 4,391,710 to A. J. Gordon wherein a plurality of holders are arranged in spaced circumferential relation to one another about a common motor drive, each holder adapted to retain an individual chamber together with a separate filter card and slide. Specifically, each holder is made up of a channel adapted to receive a slide which is overlaid by a filter card and by a correspondingly shaped end flange at an end of the sample chamber. The holder includes a clamp in order to retain the assembly of the chamber, filter card and slide together and in properly aligned relation such that the filter card will properly absorb the liquid component of the sample and permit the cells and other solids to pass through the card and be deposited onto a surface of the slide.
As noted in the hereinbefore referred to patent to Gordon, the problem associated with prior art arrangements is the assembly operation to be carried out in the installation of the sample chambers in conjunction with the rotating carrier of the centrifuge and specifically to achieve proper alignment between the chamber, filter card and receiving surface of the slides. Such arrangements in the past have been difficult to assemble and manipulate especially when the material being centrifuged must be handled under conditions of containment in order to prevent the escape of toxic or noxious matter. Nevertheless, in accordance with the teachings of the patent to Gordon, it is necessary to preassemble each chamber, filter card and slide as a preliminary to mounting in the holder. Upon completion of the centrifuge operation, removal of the assembled components and disassembly of same to recover the sample to be examined, the holders and chambers must then be cleaned and sterilized individually for subsequent reuse.
Notwithstanding that the centrifuge disclosed in the patent to Gordon offers definite advantages and improvements over the prior art in the handling and sampling of body fluids, there exists the need for a unitary cytology chamber and filter card assembly which not only minimizes the steps of preassembly with the microscopic slide or glass as a preliminary to placement in the holder, but assures accurate alignment between the elements and, most importantly, precludes reuse of the chamber and filter card. The latter is particularly important in the handling of body fluids containing certain diseases where it is vital that the chamber of filter card not be reused after a particular sampling operation. Joining of the two components together as a unitary assembly avoids any temptation on the part of the operator to reuse either or both in subsequent sampling operations. It is therefore proposed to provide a unitary chamber and filter card in which the components are permanently united together in properly aligned relation and cannot be separated without destroying the interface between the two; yet in uniting the two together avoids any danger of contamination of the sample and offers an extremely simple but effective way of assembling the components so as to prevent their reuse and assure more rapid loading and unloading of the samples with respect to their respective holders.
Other representative U.S. Letters Patent in this field are U.S. Pat. No. 4,265,762 to D. L. Brenholt; U.S. Pat. No. 4,344,562 to A. Ricci; and U.S. Pat. No. 4,357,240 to R. C. Mehra et al. However, none suggests or discloses a manner and means by which a filter card may be permanently affixed to an end flange on a chamber and in properly aligned relation so as to form a disposable unit and in such a way as to preclude reuse of the assembly in the manner devised according to the present invention.